Maternal gestational weight gain (GWG) and rapid infant weight gain in the first months of life are important determinants of a child's life-long rik of obesity. Maternal GWG has been associated with both rapid infant weight gain and the child's later development of insulin resistance, hypertension, and obesity. It is particularly important to improve these outcomes in the Latino population, where rates of obesity are higher than the general population. The proposed study (entitled GROW Baby) will create a new cohort of Latina women who are already enrolled in a randomized behavioral intervention to prevent preschool obesity and subsequently become pregnant during the study period. The Growing Right Onto Wellness trial (GROW) has enrolled 610 maternal- preschool child pairs (ages 3-5). The intervention teaches a behavioral toolkit focused on healthy nutrition, physical activity, media use, and sleep for both mother and child. The control condition is a school readiness program. By developing this new cohort of Latina women who become pregnant during the study period, the proposed research aims to test how behavioral interventions delivered before and during pregnancy support healthy maternal GWG and healthy infant growth. A committed primary mentor and a multi-disciplinary team of co-mentors will oversee the candidate's progression to becoming an independently funded physician scientist with a focus on improving health outcomes related to obesity in families, particularly those from the Latino community. The career development plan consists of advanced coursework in community-engaged research methodology and participation in 1) an ongoing behavioral intervention; 2) community engagement activities; and 3) local and national conferences. This mentored career award integrates a research strategy that advances pediatric obesity prevention during pregnancy with a career development plan that applies community engaged research methodology to behavioral interventions. Through the conduct of the proposed research, the candidate will advance the field of pediatric obesity prevention by understanding how a behavioral intervention implemented before and during pregnancy could support healthy weight for both mother and child.